Conventionally, known motor driving devices (see, for example, Patent Document 1) for a hybrid vehicle incorporating an engine and a motor that serve as drive sources include: an inverter for driving the motor; an accumulator battery, such as a large-capacitance capacitor that supplies power to the motor via the inverter and also stores power generated by the motor; a condenser connected in parallel with the accumulator battery; a means for adjusting the generated voltage of the motor; and a contactor connected in series between the accumulator battery and the condenser. In a motor driving device of such a configuration, the motor can be used as a generator while the generated voltage of the motor is adjusted when the engine starts. Accordingly, even if the voltage of the accumulator battery is substantially zero when the engine starts, the accumulator battery will be charged, and the motor can be driven using the charged accumulator battery.
Patent Document 1: Japanese Patent Application Laid-Open No. 2006-314172